What is the primary effect of tool chatter on a machined workpiece?

The primary effect of tool chatter on a machined workpiece is the creation of surface imperfections. Tool chatter refers to vibrations that occur during the cutting process, which can lead to an inconsistent removal of material. These vibrations cause the cutting tool to lose contact with the workpiece intermittently or to cut inconsistently, resulting in a rough surface finish characterized by marks, grooves, or waviness. This negatively impacts the integrity and accuracy of the machined part, making it visually unappealing and potentially affecting its functional performance.

In contrast, improved finish, increased tool life, and decreased productivity do not accurately describe the result of tool chatter. High-quality finishes and prolonged tool life are typically associated with stable machining conditions, while chatter generally leads to poorer surface quality and can actually reduce productivity due to the need for additional finishing processes or rework.